Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany.
Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany.
Environ Sci Process Impacts. 2019 Nov 1;21(11):1852-1863. doi: 10.1039/c9em00290a. Epub 2019 Sep 2.
Perfluoroalkyl acids (PFAAs) are persistent, ubiquitous environmental contaminants and their long-chain representatives are bioaccumulative. The phase-out of these compounds (e.g. PFOA and PFOS) shifted the production to alternatives. However, little is known about the bioaccumulative behaviour of the alternatives, which are still highly fluorinated. PFAAs are predominantly detected in blood, where they bind to the transport protein serum albumin. This sorption can be described by the albumin/water partition coefficient. It is unclear whether the partition coefficients of the alternatives are lower than or in the same range as those of classical PFAAs. We determined albumin/water partition coefficients for seven perfluoroalkyl carboxylates, three perfluoroalkane sulfonates and four alternatives by dialysis experiments in a physiologically representative system. Quantification was done by LC-MS/MS and a mass balance approach. Logarithmic albumin/water partition coefficients for PFAAs range from 2.8 to 4.8 [L kg] and increase with increasing chain length. Perfluorinated sulfonates sorb more strongly than their carboxylate counterparts. The albumin/water partition coefficients for the alternatives (HFPO-DA, DONA, 9Cl-PF3ONS and PFECHS) are in the same range as for classical PFAAs. Structural modifications such as the introduction of ether groups into the chain do not reduce sorption to albumin, whereas the chlorine atom in 9Cl-PF3ONS seems to even increase the sorption to albumin. We further investigated whether the sorption strength could be affected in the presence of medium- or long-chain fatty acids. Binding competition between medium-chain fatty acids and PFAAs appeared to be possible. However, the presence of physiologically more relevant long-chain fatty acids should not alter the albumin/water partition coefficients of PFAAs.
全氟烷基酸（PFAAs）是持久性、普遍存在的环境污染物，其长链代表物具有生物蓄积性。这些化合物（例如 PFOA 和 PFOS）的淘汰促使生产转向替代品。然而，对于这些替代品仍然高度氟化的生物蓄积行为知之甚少。PFAAs 主要在血液中检测到，在血液中它们与转运蛋白血清白蛋白结合。这种吸附可以用白蛋白/水分配系数来描述。目前尚不清楚替代品的分配系数是否低于或处于与经典 PFAAs 相同的范围内。我们通过在生理代表性系统中进行透析实验，确定了七种全氟烷基羧酸酯、三种全氟烷磺酸酯和四种替代品的白蛋白/水分配系数。通过 LC-MS/MS 和质量平衡方法进行定量。PFAAs 的对数白蛋白/水分配系数范围为 2.8 至 4.8 [L kg]，并随链长的增加而增加。全氟磺酸酯比其羧酸酯对应物更强烈地吸附。替代品（HFPO-DA、DONA、9Cl-PF3ONS 和 PFECHS）的白蛋白/水分配系数与经典 PFAAs 相同。结构修饰，如在链中引入醚基团，不会降低对白蛋白的吸附，而 9Cl-PF3ONS 中的氯原子似乎甚至增加了对白蛋白的吸附。我们进一步研究了在存在中链或长链脂肪酸的情况下，吸附强度是否会受到影响。中链脂肪酸与 PFAAs 之间的结合竞争似乎是可能的。然而，生理上更相关的长链脂肪酸的存在不应改变 PFAAs 的白蛋白/水分配系数。
